Effects of chelators on the acute toxicity and bioavailability of aluminium to Tetrahymena pyriformis

Sauvant, M.P.; Pépin, D.; Bohatier, Jacques; Grolière, C. A.

doi:10.1016/s0166-445x(99)00015-6

Cited by 26 publications

(11 citation statements)

References 54 publications

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“…In Al-and Pb-Al-treated cells (Figs. 2c and d, respectively), the scattered appearance of diverse sized electron-dense deposits in vacuoles can be attributed to the deposition of Al as stated by Sauvant et al [34]. They identified various electron-dense granules with dots inside numerous vacuoles by X-ray microanalysis as Al precipitates in cells of Tetrahymena pyriformis exposed to Al.…”

Section: Toxicity Of the Metals At The Subcellular Levelmentioning

confidence: 66%

Exposure of Dunaliella tertiolecta to Lead and Aluminum: Toxicity and Effects on Ultrastructure

Saçan

Öztay

Bolkent

2007

Biol Trace Elem Res

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The growth response of the marine alga Dunaliella tertiolecta to different concentrations of lead and aluminum was investigated. Both metals had a stimulatory effect at low concentration and an inhibitory effect at high concentration (hormesis). The IC25 values of lead are 8.43, 7.29, and 6.74 mg L-1 for 24, 48, and 72 h, respectively. The corresponding values for aluminum are 30.54, 22.42, and 18.16 mg L-1. Although it seems that the two metals are not directly toxic to the alga at the concentrations found in the environment, as implied by the IC25 values and the environmental concentrations of the metals, low concentrations of both metals, alone and in combination, affected the ultrastructure. The growth of batch-grown cells exposed to 0.5 mg L-1 lead and aluminum, alone and combined, during the 24-h exponential phase was investigated. The same cells were also examined under an electron microscope to determine the biological effects of the two metals on the ultrastructure. The most obvious effects of lead were disrupted thylakoidal membranes, accumulated polyphosphate bodies and vacuoles, and lead precipitates on the cell surface. These ultrastructural alterations were partially present in aluminum-treated and lead-aluminum-treated cells. In joint exposure, the most important change was the lysis of the cell membrane. Aluminum and lead seem to act synergistically on the cell membrane leading to cell membrane lysis.

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Section: Toxicity Of the Metals At The Subcellular Levelmentioning

confidence: 66%

Exposure of Dunaliella tertiolecta to Lead and Aluminum: Toxicity and Effects on Ultrastructure

Saçan

Öztay

Bolkent

2007

Biol Trace Elem Res

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“…Although the mechanisms by which heavy metals affect the microorganisms is not clear, authors have described copper as an essential metal that accumulated in the mitochondria [29] with its distribution observable as small electron-dense dots [17,18]. Alteration on Tetrahymena morphology after aluminium exposure was reported by Sauvant and collaborators [26] who observed the presence of large and irregular-shaped monster cells in treated cultures. These morphological abnormalities were detected in zinc-treated cells but not in copper cultures.…”

Section: Discussionmentioning

confidence: 94%

A comparative study using a fluorescence-based and a direct-count assay to determine cytotoxicity in Tetrahymena pyriformis

Dias

Lima

2002

Research in Microbiology

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A novel cellular cytotoxicity assay using two fluorescent dyes was developed as an alternative method to the standard direct count of viable protozoa under light microscopy. The compound calcein AM is a non-fluorescent substance that diffuses passively across intact cell membranes and is converted by intracellular esterases to the green fluorescent calcein, which is retained in viable cells. The addition of EthD-1 that binds to DNA stained nuclei of dead cells red. The experiments were carried out in order to assess viability in the freshwater ciliate Tetrahymena pyriformis after exposure to eight surfactants, two of each representing one of four ionic class (non-ionic, anionic, cationic and amphoteric), and two heavy metals, copper and zinc, at several concentrations. In earlier time exposure, less than one hour of contact with surfactants at sublethal concentrations, the fluorescent method is more sensitive and provides more accurate results than direct counting under light microscopy. In contrast, with increasing time exposure, the results obtained by the two methods were similar. Calcein was shown to be a poor viability marker in the presence of zinc and copper since the fluorescence intensity was affected by the metal presence. However, the fluorescent method offers new opportunities to use advanced techniques, such as flow cytometry, to assess cytotoxicity in protozoa.

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“…Thus, a rodenticide bioconcentration was induced which facilitated the enzymatic lysis of the rodenticide humate chelates in the food vacuoles and the liberation of rodenticide under a free and toxic form into the cells. In this case, HA may act only as a carrier [45]. In such a case, the more the rodenticide associates with HA, the more the rodenticide penetrates into the cells and consequently is toxic for the HaCaT.…”

Section: Resultsmentioning

confidence: 99%

Rodenticide–humic acid adsorption mechanisms and role of humic acid on their toxicity on human keratinocytes: chromatographic approach to support the biological data

André

Guyon

Guillaume

2004

Journal of Chromatography B

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Effects of chelators on the acute toxicity and bioavailability of aluminium to Tetrahymena pyriformis

Cited by 26 publications

References 54 publications

Exposure of Dunaliella tertiolecta to Lead and Aluminum: Toxicity and Effects on Ultrastructure

Exposure of Dunaliella tertiolecta to Lead and Aluminum: Toxicity and Effects on Ultrastructure

A comparative study using a fluorescence-based and a direct-count assay to determine cytotoxicity in Tetrahymena pyriformis

Rodenticide–humic acid adsorption mechanisms and role of humic acid on their toxicity on human keratinocytes: chromatographic approach to support the biological data

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